CS-iTWM-05 Manhole Cover Monitoring Sensor

Users Manual

（CS-iTWM-05-SS）

（REV:A）

Ⅰ

Contents

1 Overview.........................................................................................................................................................1

1.1 Introduction.............................................................................................................................................1

1.2 Working principle...................................................................................................................................1

2 Technical indicators.................................................................................................................................3

2.1 Main technical parameters...................................................................................................................3

2.2 Dimensions.................................................................................................................................................3

3 Instructions for use.................................................................................................................................5

3.1 Installing the SIM Card.......................................................................................................................5

3.2 Powering on the product and replacing the battery...................................................................5

3.3 Network Description...............................................................................................................................5

3.4 Communication Protocol.........................................................................................................................6

4 Installation method...................................................................................................................................7

4.1 Installation of power double-layer manhole cover.....................................................................7

4.2 Installation of non-metal composite manhole cover...................................................................8

4.3 Installation of iron manhole cover...............................................................................................10

5 selection guide.........................................................................................................................................13

6 Accessories.................................................................................................................................................15

7 Precautions.................................................................................................................................................15

7.1 Terminal networking is unsuccessful.............................................................................................15

7.2 The product may be underreported due to the following reasons.........................................15

8 statement.....................................................................................................................................................15

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CS-iTWM-05 Manhole Cover Monitoring Sensor

User Manual

1 Overview

1.1 Introduction

The manhole cover monitoring sensor is installed on the back of the manhole cover, which

is placed horizontally as a normal state. The alarm condition is trigerred when the manhole cover

is tilted and the inclination angle is over 10° (configurable). The alarm signal is sent to

the monitoring center through wireless transmission. Then, the monitoring center analyzes the

data and judges the alarm.

The device, shown in Figure 1, can provide three wireless communication modes: LoRaWAN, NB-IoT

and GPRS. It is powered by battery, and features easy mounting, long battery life, high detection

accuracy and stable operation.

Figure 1 Manhole cover monitoring Sensor

1.2 Working principle

The manhole cover monitoring sensor is installed on the back of the manhole cover. It measures

the current inclination angle of the manhole cover through the acceleration sensor. The alarm

condition is trigerred when the manhole cover is tilted and the inclination angle is over 10°

(configurable). The alarm signal is sent to the monitoring center through wireless transmission.

The device supports setting the timing reporting interval, and alarm angle threshold（default

10°）. In the normal condition, the device sends the report message at the time interval of

the periodic report. The status flag in the message can be used to determine whether it’s the

alarm or normal status. When the device detects that the battery voltage is low, the device reports

a low voltage warning message. The device sends the status information according to the set timing

interval.

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The conditions of abnormal movement are: ABS(current angle - initial angle) ＞ alarm angle

threshold. When the condition is met, an alarm message is sent.

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2 Technical indicators

2.1 Main technical parameters

The main technical indicators of the manhole cover monitoring sensor are shown in Table 1.

Table 1 Main technical parameters

Name Technical parameters Remarks

Working frequency

433MHz/470MHz/868MHz/915MHz LoRaWAN

B1/B3/B5/B8/B20 NB-IoT

850/900/1800/1900MHz GPRS

Equipment type Class A LoRaWAN

Antenna interface FPC 天线

Operating Voltage Lithium batteryER26500+SPC1550（3.6V）ER26500+SPC1550

Not rechargeable

Battery Life 3-5yearsTest condition: Work normally and

report data up to twice a day

Maximum working current

＜200mA LoRaWAN

＜350mA NB-IoT

＜2000mA GPRS

Sleeping current ＜25.0uA

Protection level IP68

Shell material

PC+ABS

Anti-aging, anti-corrosion,

anti-collision materials

Operating temperature(-25～+85)℃ Consumer SIM Card

(-40～+85)℃ Industrial SIM Card/LoRaWAN

Storage temperature (-40～+85)℃

Measuring range 0°～ 180°

Measurement accuracy ±2°

2.2 Dimensions

The shape and size of the manhole cover monitoring sensor are shown in Figure 2.

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Figure 2 Dimensional drawing

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3 Instructions for use

3.1 Installing the SIM Card

For NB-IOT and GPRS communication devices, users can open the device’s cover and install

SIM cards themselves. After the installation is complete, put the cover on and tighten the screws

to ensure waterproof performance.

It is recommended to use the SIM card provided by the manufacturer for the best protection.

The user can also provide the SIM card and the manufacturer install it before leaving the factory.

3.2 Powering on the product and replacing the battery

The sensor is powered by a disposable lithium battery(optional accessories). If it is equipped

with a battery by factory, the product is not powered when it leaves the factory. When the battery

is low and the device reports the low voltage alarm message, please replace the battery of same

type (model: ER26500+SPC1550 battery pack, consulting the manufacturer for other equivalent

battery type).

The steps to install or replace the battery are shown in Figure 3:

Figure 3 Battery installation or replacement

Open the cover to plug in the battery connector, the product is powered on.

Note: After installing the battery, cover the battery compartment cover, tighten the screws,

and make sure the sealing ring is properly installed. If the seal is missing or the screws are

not tightened, it will lose the waterproof performance.

3.3 Network Description

3.3.1 LoRaWAN Networking Instructions

LoRaWAN devices support OTAA and ABP network access. The network access parameters can be

default parameters. The user can also provide the network access parameters before the product

leaves the factory. The user can also choose to configure the network access parameters.

If you choose to configure your own network configuration, you can obtain configuration

documentation from the manufacturer.

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The DEVEUI is printed on the product casing and can be used directly when entering the network.

3.3.2 NB-IoT Networking Instructions

The IMEI number is printed on the product casing and can be used directly when accessing

certain platforms. The device supports UDP and COAP communication protocols.

3.4 Communication Protocol

Product communication protocol related documents are available from the manufacturer.

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4 Installation method

4.1 Installation of power double-layer manhole cover

The double-layer cover is divided into upper bearing layer, and the lower protective layer.

The device can only be installed on protective layer.

The construction steps and technical requirements are as follows:

Installation accessories：CS-iTWM-A03

Figure 4 Installation instruction with CS-iTWM-A03

1）The maintenance worker uses a special tool to open the lock of the upper manhole cover,

removes the upper manhole cover.

2）Pull up the lower protective cover, place it on the road.

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3）Place the monitoring device flat on the pre-installation position of the lower protective

cover, use the pencil to align the 3-φ8mm holes centers to describe the pre-punching position

on the lower cover;

4）Remove the monitoring device, install the φ6 drill with the hand-held electric drill,

and drill on the lower cover, make sure the drill right at the center of drawing hole;

5）Open the battery cover, protect the cover from being stained with dirt, install the battery,

put on the battery cover, and tighten the screws;

6）Put the 3-M6*35mm hexagon socket bolts with spring washers and flat washers through the

3-φ8mm holes, tighten the 3-M6 nut with the inner hexagonal wrench to fix the device onto the

lower cover;

7）Place the lower cover equipped with the monitoring device back in the original position.

The on-site engineer will arm the alarm state, and put the manhole cover back in the natural

state, then take it out and place it on the road surface to observe the alarm state. After the

operation is completed, place the manhole cover back in the original position, and record the

current GPS latitude and longitude;

8）After the installation is completed, the maintenance worker put the upper manhole cover

back and lock it with the special tool.

4.2 Installation of non-metal composite manhole cover

For composite or non-metallic manhole covers, in order not to damage the structure of the

manhole cover itself, the monitoring terminal can be fixed onto the manhole cover using special

kits, shown as follows.

For such manhole covers, the installation method of the monitoring device is as follows:

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Installation accessories：CS-iTWM-A02

1）Select the longitudinal beam or beam with higher dimension , use the proper U-shaped

stainless steel channel steel, shown as below, the width A of the channel should be slightly

larger than the width of the beam cover beam, and cut the channel into a small section of length

C. The dimension C should be less than the gap width between the staggered longitudinal beams

on the manhole cover to ensure that the U-Steel can insert in between the manhole beams.

Processing instruction of U-steels

2）Cut the U-steel into small sections as follows.

Install the stainless steel rivet nuts on the three sides of the U-steel. The positions

of each side are shown in the figure below.

Installation instruction with rivet nut

U-steels

U-steel M6 nut

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3）Make the U-steels with the rivet nut clamped and fixed to the beams with the M6 taper

end screws, tighten the M6 hex nuts to lock it.

Installation instruction with U-steels

4）Install the device on the fixed U-steels as shown in the figure.

Installation Instruction with CS-iTWM-A02

4.3 Installation of iron manhole cover

M6 taper end screws

M6 hex nuts

beams

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For iron manhole cover, as shown in the figure, the monitoring device is mounted on the bracket,

which is installed on any side of the hexagonal rib at the center of the manhole cover.

Iron manhole cover Bracket

The construction steps and technical requirements are as follows:

Installation accessories：CS-iTWM-A01

Installation Instruction with CS-iTWM-A01

1）The maintenance worker opens the manhole cover. After the manhole cover is pulled open,

make sure it being placed stably;

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2）Choose one side of the hexagonal rib that is convenient for operation, and place the gasket

in the pre-installation position, and use a pencil to align the 2-φ6.5mm hole centers on the

gasket;

3）Use a hand-held electric drill with a φ6 cobalt drill bit, and drill 2 holes at the fixed

position, make sure the drill right at the center of drawing holes;

4）Place the 2-M6*35mm hex socket bolts with spring washers and flat washers in sequence,

as shown in Figure 3, through the 2 holes on the manhole cover, mounting bracket and gasket.

Drip the thread glue on the bolts and nuts, pre-tighten the 2-M6 nuts by hand, adjust the top

surface of bracket to the same level of the bottom of the manhole cover, and then tighten the

bolts and nuts with the inner hexagonal wrench.

5）Open the battery cover, protect the cover from being stained with dirt, install the battery,

put on the battery cover, and tighten the screws;

6）Insert the 3-M6*25 hex socket bolts one by one, with the spring washer and flat washer,

through the 3-φ8 holes on the mounting bracket. Drip the thread glue on the bolts and nuts,

screw and pre-tighten them by hands, then use the inner hexagon wrench to tighten the bolts and

nuts;

7）The on-site engineer tests the alarm state of the monitoring device, puts the manhole

cover to the horizontal position, and tests the automatic disarming state. After testing 2 times,

place the manhole cover back in the original position, and record the current GPS latitude and

longitude;

8）After the installation is completed, reset the manhole cover, tidy tools & the site, make

the mark, and remove the enclosure at last.

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5 selection guide

Model

CS-iTWM-05

Communication

LW LoRaWAN

NB NB-IoT

G GPRS

Frequency

B1 NB-IOT

B3 NB-IOT

B5 NB-IOT

B8 NB-IOT

B20 NB-IOT

BG B1/B3/ B5/ B8/B20（NB-IOT）

EU433 433MHz（LORAWAN）

CN470 470MHz（LORAWAN）

EU868 868MHz（LORAWAN）

US915 915MHz（LORAWAN）

AS923 923MHZ（LORAWAN）

*Please indicate the other frequency bands, including GPRS

scenes.

CS-iTWM-05 NB B8

Example：

CS-iTWM-05_NB_B8： NB-IoT ，B8。

CS-iTWM-05_LW_868：LORAWAN 868MHZ。

CS-iTWM-05_G_900/1800：GPRS 900/1800MHZ。

Note:

Our company can provide Industrial SIM Card and Consumer SIM Card. If the product is required

to be equipped with SIM Card, please indicate the type of SIM Card when purchasing. Please refer

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to Table 1 in Section 2.1 for the operating temperature range of Industrial SIM Card and Consumer

SIM Card.

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6 Accessories

Customers can choose the attachment according to the selection table shown in Table 2.

Note: If you have questions about attachment selection, please contact your supplier.

Table 2 Annex selection table

Annex Description Remarks

PL2303

USB to UART-TTL adapter. Customers use the product when

they make their own products. If they are not configured,

they are not needed.

ER26500+SPC1550The product comes with a battery when it leaves the factory.

If you need extra battery, please specify when purchasing.

CS-iTWM-A01Mounting fittings for the manhole terminal of the end

of the manhole cover

CS-iTWM-A02Mounting fittings for manhole cover with "well" shaped beams

on the back of the non-metallic composite manhole cover

CS-iTWM-A03Mounting fittings installed in the second floor or

direct perforated manhole terminal

Factory default

install accessory

7 Precautions

7.1 Terminal networking is unsuccessful

a) Check if the node module is registered in the server;

b) Check if the battery has power or the battery is too low

c) Check if there is a fee for the SIM card and whether the data service is open;

d) Please contact the supplier for other questions.

7.2 The product may be underreported due to the following reasons

a) The SIM card is damaged or the SIM card is not installed;

b) The battery is exhausted;

c) False negatives occur when the signal is not good or when the signal is blocked;

d) Other special circumstances

8 statement

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The company reserves the right to modify the specifications and contents of this manual,

and is subject to change without prior notice. Due to product updates, some details of this

document may not match the product, please refer to the actual product, the right to interpret

this document belongs to the company.

_________________________________

1　Overview1.1　Introduction1.2　Working principle

2　Technical indicators2.1　Main technical parameters2.2　Dimensions

3　 Instructions for use3.1　Installing the SIM Card3.2　Powering on the product and replacing the battery3.3　Network Description3.3.1　LoRaWAN Networking Instructions3.3.2　NB-IoT Networking Instructions

3.4　Communication Protocol

4　 Installation method4.1 Installation of power double-layer manhole cov4.2 Installation of non-metal composite manhole co4.3 Installation of iron manhole cover

5　 selection guide6　Accessories7　Precautions7.1　Terminal networking is unsuccessful7.2　The product may be underreported due to the follow

8　statement